Jayah Ram-Jackson allegedly jumped to her death Thursday. Photo: Facebook

A 15-year-old girl who hinted at suicide on Facebook earlier this week jumped to her death from her grandmother’s Upper West Side high-rise Thursday, police sources said.

Jayah Ram-Jackson’s body landed on the West 94th Street side of the Amsterdam Avenue building at around 10:40 a.m., and she was pronounced dead at the scene, sources said.

Police said Ram-Jackson got onto the roof of the 27-story building through an unlocked door.

“I heard something that I wish I could unhear,” said a woman who works nearby and identified herself only as Jen. “It sounded like a ‘thump,’ or a ‘poof.’ I didn’t know what it was at first. It sounded like snow falling off the building.”

Shocked neighbors said the girl, who lived two blocks away on West 96th Street, often visited her grandma at the building.

“The doorman let her in because they’ve all seen her before,” said one neighbor. “They must have assumed she was visiting the grandmother. She went straight to the roof and jumped.”

Another neighbor said the grandmother wasn’t even aware the girl had been by the building and had to be hospitalized when she heard the news.

Sources said Ram-Jackson struggled with mental-health issues and had a history of depression and was known to cut herself.

“I’m actually just going to wait for someone to make a petition for me to kill myself because it’s inevitable . . . like, we all see it coming,” Ram-Jackson posted on her Facebook page Tuesday.